TECHNICAL FIELD
[0001] The present invention relates to the field of wireless communication, and in particular,
to a wireless local area network data transmission method and apparatus.
BACKGROUND
[0002] With rapid development of communications technologies, a wireless local area network
(WLAN for short) technology based on an IEEE 802.11 standard is widely used. A physical
layer (PHY for short) based on an IEEE 802.11n/ac protocol uses an orthogonal frequency
division multiplexing (OFDM for short) technology.
[0003] A WLAN network may include multiple access points (AP for short) and multiple stations
(STA for short). Each AP may be associated with multiple STAs, and each AP may transmit,
by using a radio channel, wireless local area network data with a STA associated with
the AP. An AP transmits a physical layer protocol data unit (PPDU for short) with
a STA associated with the AP.
[0004] In the prior art, a receive end STA can determine whether information on a PPDU belongs
to the STA only after parsing the entire PPDU. Consequently, a large amount of unnecessary
information is parsed during the process, thereby reducing transmission efficiency.
Therefore, based on an IEEE 802.11ax protocol, a wireless local area network data
transmission manner is urgently needed to improve data transmission efficiency.
[0005] US 2012/0051312 A1 discloses a method of a transmission station (STA) transmitting a frame in a Wide
Local Area Network (WLAN) system. The method includes transmitting a Direct Link Setup
(DLS) request frame, requesting direct link setup with a destination STA, to an Access
Point (AP) and receiving a DLS response frame from the AP in response to the DLS request
frame, wherein the DLS request frame comprises an Association ID (AID) allocated from
the AP to the transmission STA in a process of the transmission STA being associated
with the AP.
[0006] US 2012/0314636 A1 discloses a method for facilitating power saving in a wireless network, where a PHY
header is generated to include an indication of a duration of a PHY data unit. A preamble
is also generated. The PHY data unit is generated to include the preamble and the
PHY header, and the PHY data unit is transmitted.
SUMMARY
[0007] Embodiments of the present invention provide a wireless local area network data transmission
method and apparatus, which are used for improving data transmission efficiency. This
problem is solved by the subject matter of the independent claims. Further implementation
forms are provided in the dependent claims.
[0008] According to a first aspect, a wireless local area network communications apparatus
as disclosed by claim 1 is provided.
[0009] According to a second aspect, a wireless local area network communications apparatus
as disclosed by claim 5 is provided.
[0010] According to a third aspect, a wireless local area network data transmission as disclosed
by claim 9 is provided.
[0011] According to a fourth aspect, a wireless local area network data transmission as
disclosed by claim 13 is provided.
[0012] In the embodiments of the present invention, a control domain of a PLCP header domain
in a PPDU constructed by an AP carries identifier information of the AP, duration
information, and an identifier of at least one STA, so that a STA may obtain the identifier
information of the AP, the duration information, and the identifier of at least one
STA by parsing only the control domain of the PLCP header domain. Therefore, the STA
may determine whether the control domain of the PPDU includes an identifier of the
STA and a wildcard STA identifier according to an identifier of the AP and the identifier
of at least one STA; and further, if the STA determines that the control domain of
the PPDU does not include the identifier of the STA or the wildcard STA identifier,
the STA configures an NAV according to the duration information. In this process,
only the control domain of the PPDU is parsed, thereby improving data transmission
efficiency.
BRIEF DESCRIPTION OF DRAWINGS
[0013] To describe the technical solutions in the embodiments of the present invention more
clearly, the following briefly describes the accompanying drawings required for describing
the embodiments. Apparently, the accompanying drawings in the following description
show merely some embodiments of the present invention, and a person of ordinary skill
in the art may still derive other drawings from these accompanying drawings without
creative efforts.
FIG. 1 shows a data transmission system according to an embodiment of the present
invention;
FIG. 2 is a schematic structural diagram of an MPDU and a PPDU in the prior art;
FIG. 3 is a schematic diagram of an architecture for data transmission between an
AP and a STA in the prior art;
FIG. 4 is a schematic diagram of a frame structure of an MPDU in the prior art;
FIG. 5 is a schematic diagram of a frame structure of a PPDU in the prior art;
FIG. 6 is a schematic diagram of a frame structure of a PPDU applied to an embodiment
of the present invention;
FIG. 7 is a schematic structural diagram of a wireless local area network communications
apparatus according to the disclosure;
FIG. 8 is a schematic structural diagram of a wireless local area network communications
apparatus according to the disclosure;
FIG. 9 is a schematic structural diagram of a wireless local area network communications
apparatus according to the disclosure;
FIG. 10 is a schematic structural diagram of a wireless local area network communications
apparatus according to the disclosure;
FIG. 11 shows a data transmission method according to the disclosure;
FIG. 12 is a schematic diagram of a time length specified by duration information
in a data transmission method according to the disclosure;
FIG. 13a is a schematic diagram of a frame structure of an MPDU in a data transmission
method according to the disclosure;
FIG. 13b is a schematic diagram of a structure of some frames in a frame control field
of an MPDU in a data transmission method according to the disclosure;
FIG. 13c is a schematic diagram of a frame structure of an MPDU in a data transmission
method according to the disclosure;
FIG. 13d is a schematic diagram of a frame structure of an MPDU in a data transmission
method according to the disclosure;
FIG. 13e is a schematic diagram of a frame structure of an MPDU in a data transmission
method according to the disclosure;
FIG. 14 shows a data transmission method according to the disclosure;
FIG. 15 is a schematic structural diagram of a wireless local area network communications
apparatus according to the disclosure; and
FIG. 16 is a schematic structural diagram of a wireless local area network communications
apparatus according to the disclosure.
DESCRIPTION
[0014] In embodiments of the present invention, a control domain of a PLCP header domain
in a PPDU constructed by an AP carries identifier information of the AP, duration
information, and an identifier of at least one STA, so that a STA may obtain the identifier
information of the AP, the duration information, and the identifier of at least one
STA by parsing only the control domain of the PLCP header domain. Therefore, the STA
may determine whether the control domain of the PPDU includes an identifier of the
STA and a wildcard STA identifier according to an identifier of the AP and the identifier
of at least one STA; and further, if the STA determines that the control domain of
the PPDU does not include the identifier of the STA or the wildcard STA identifier,
the STA configures an NAV according to the duration information. In this process,
only the control domain of the PPDU is parsed, thereby improving data transmission
efficiency.
[0015] A standard for a next generation wireless local area network that is currently being
formulated is IEEE 802.11ax, which intends to improve efficiency of a wireless local
area network in a practical network deployment scenario, and is therefore referred
to as a high-efficiency wireless local area network (English: High Efficiency WLAN,
HEW for short). A PHY based on the IEEE 802.11ax uses an Orthogonal Frequency Division
Multiple Access (English: Orthogonal frequency division multiplexing address, OFDMA
for short) technology.
[0016] A WLAN may include multiple access points (English: Access Point, AP for short) and
multiple stations (English: Station, STA for short). Each AP may be associated with
multiple STAs, and each AP may transmit, by using a radio channel, wireless local
area network data with a STA associated with the AP. The embodiments of the present
invention are applied to a WLAN system, and the WLAN system includes an AP and a STA.
FIG. 1 is a simple schematic diagram of a WLAN system applied to an embodiment of
the present invention. The system in FIG. 1 includes one or more AP601s and one or
more STA602s. Wireless communication between the AP601 and the STA602 is performed
by using an OFDMA technology.
[0017] An AP may also be referred to as a wireless access point, a bridge, a hotspot, or
the like, and may access a server or a communications network.
[0018] A STA may also be referred to as a user, or may be a wireless sensor, a wireless
communications terminal, or a mobile terminal, for example, a mobile phone (or referred
to as a "cellular" phone) supporting a Wi-Fi communication function or a computer
with a wireless communication function. For example, the STA may be a portable, pocket-sized,
handheld, computer built-in, wearable, or in-vehicle wireless communications apparatus
that supports the Wi-Fi communication function and exchanges communications data,
such as voice or data, with a radio access network.
[0019] Identifier information of the AP mentioned in this embodiment of the present invention
is used to uniquely identify the AP within a network coverage area. The identifier
information of the AP may be a basic service set identifier (English: Basic Service
Set Identifier, BSSID for short), or a part of the BSSID, for example, 7 lowest bits
in the BSSID, an identifier generated based on the BSSID, or an identifier of the
AP pre-allocated by a network.
[0020] Duration information mentioned in this embodiment of the present invention is used
by the STA to configure an NAV of the STA by using the data, and the duration information
may be indicated by using 15 bits.
[0021] FIG. 2 exemplarily shows a structural diagram of an MPDU and a PPDU in the prior
art. FIG. 3 exemplarily shows a diagram of an architecture for data transmission between
an AP and a STA in the prior art. As shown in FIG. 2 and FIG. 3, when an AP performs
data transmission with a STA associated with the AP, the AP generally encapsulates
an MSDU as a Medium Access Control protocol data unit (English: Medium Access Control
Layer Protocol Data Unit, MPDU for short) by attaching a Medium Access Control (English:
Medium Access Control, MAC for short) header domain to the Medium Access Control service
data unit (English: Medium Access Control Service Data Unit, MSDU for short) at an
upper-layer logical link control layer (English: Logical Link Control, LLC for short);
the AP encapsulates the MPDU as a physical layer protocol data unit (English: Phyical
Layer Protocol Data Unit, PPDU for short) by attaching a protocol processing unit
(English: PLCP protocol data unit, PLCP for short) header domain to the MPDU. The
AP transmits the PPDU with a STA associated with the AP.
[0022] FIG. 4 is a simple schematic diagram of a format of an MPDU in the prior art. As
shown in FIG. 4, frame control (Frame Control), duration/identifier (Duration/ID),
an address 1, and a last frame check sequence (frame check sequence, FCS for short)
field are included in each MPDU. An address 2, an address 3, sequence control, an
address 4, quality of service (English: Quality of Service, QoS for short) control,
high-throughput (English: High-throughput, HT for short) control, and a frame body
(English: Frame Body) are included in a specific frame.
[0023] The frame control field is used to indicate a type of a PPDU.
[0024] A duration message is used by a STA to configure an NAV of the STA, so as to ensure
that no data is sent during a time length of the duration message, thereby reducing
channel interference.
[0025] The address 1 is a receiver address (RA for short) of the MPDU, and the address 2
is a transmitter address (TA for short) of the MPDU. When data is downlink data sent
by an AP to a STA, the address 1 is a MAC address of the receive end STA, and the
address 2 is a MAC address of the transmit end AP; or when data is uplink data sent
by a STA to an AP, the address 1 is a MAC address of the receive end AP, and the address
2 is a MAC address of the transmit end STA.
[0026] FIG. 5 shows a format of an OFDM PPDU in the prior art. As shown in the figure, three
sections of signals in the first 20 µs include an 8 µs legacy short training field
(L-STF for short), an 8 µs legacy long training field (L-LTF for short), and a 4 us
legacy signal field (L-SIG for short). The L-STF is used to synchronize a STA associated
with an AP to the AP, and the L-LTF is used by the STA associated with the AP to perform
channel estimation, so as to obtain, by using coherent reception, information about
duration of a radio frame carried in the L-SIG. A very high throughput signal domain
A (VHT-SIG-A for short) carries transmission configuration parameter information of
the PPDU. A very high throughput short training field (VHT-STF for short) is used
by a receive end to perform automatic gain control (AGC). A very high throughput long
training field ( VHT-LTF for short) is used by the receive end to perform channel
estimation and coherent detection. A very high throughput signal domain B (VHT-SIG-B
for short) is used to indicate a modulation and coding scheme (MCS for short) used
by subsequent data, and a length of the MPDU transmitted. The last data domain is
used to carry the MPDU.
[0027] In the foregoing FIG. 4 and FIG. 5, the MPDU is carried in the data domain in the
last part of the PPDU. A duration message and a receiver address (address 1) or a
transmitter address (address 2) are carried in a MAC header domain of the MPDU. When
the duration message and the receiver address (address 1) are parsed out by a receive
end, if the receiver address is not a MAC address or a group address (group address)
corresponding to the receive end, the receive end configures, according to the duration
information, a network allocation vector (NAV for short) of a STA corresponding to
the receive end, so as to ensure that no data is sent within a time length of the
duration message, thereby reducing channel interference.
[0028] FIG. 6 is a simple schematic diagram of a format of a PPDU applied to an embodiment
of the present invention. As shown in FIG. 6, the PPDU includes a PLCP header domain
and a data domain. The PLCP header domain includes a legacy preamble (L-Pre for short)
and a control domain, where the control domain includes a high efficiency signal domain
(HE-SIG for short) 1 and an HE-SIG 2, and the data domain includes a downlink (DL
for short) data domain and/or an uplink (UL for short) data domain.
[0029] The L-Pre uses a preamble part that is compatible with the IEEE 802.11, where the
existing IEEE 802.11 may be an IEEE 802.11a, an IEEE 802.11g, an IEEE 802.11n, an
IEEE 802.11ac, or an IEEE 802.11ax. The L-Pre part includes an L-STF, an L-LTF, and
an L-SIG, where functions of the L-STF, the L-LTF, and the L-SIG are the same as those
of corresponding fields in the OFDM PPDU in the prior art in FIG. 5.
[0030] Data in the HE-SIG 1 in the control domain is used to indicate format configuration
of a frame that closely follows the HE-SIG 1 of a STA that performs transmission based
on the IEEE 802.11ax protocol, for example, a transmission manner of the HE-SIG 2,
or a quantity or an arrangement order of uplink and downlink data domains. The HE-SIG
1 in the control domain may be parsed by all STAs that perform transmission based
on the IEEE 802.11ax protocol.
[0031] The HE-SIG 2 in the control domain includes resource indication information configured
for the STA, where the resource indication information includes at least one STA identifier,
the STA identifier may be an identifier of a STA associated with an AP address in
the PPDU, or a wildcard STA identifier, where the wildcard STA identifier includes
identifiers of a group of STAs or all the STAs. The resource indication information
configured for the STA includes: public control information that is not included in
the HE-SIG 1, allocation information of uplink and downlink OFDMA time-frequency resource
blocks, a MAC address of the scheduled STA or identifier information of a STA associated
with an MAC address of the STA, transmission signaling corresponding to the scheduled
STA, and some other optional transmission parameter configuration information, such
as an MCS, or a quantity of spatial flows.
[0032] A difference from the prior art is: The control domain of a PPDU structure in this
embodiment of the present invention further includes an identifier of an AP, an identifier
of at least one STA, and duration information, where the identifier of the AP and
the duration information may be put in the HE-SIG 1 or the HE-SIG 2 of the control
domain, and the identifier of the STA is located in resource indication information
of the HE-SIG 2. In this way, the STA may obtain identifier information of the AP,
the duration information, the identifier of at least one STA by parsing only the control
domain of the PLCP header domain. Therefore, the STA may determine whether the control
domain of the PPDU includes an identifier of the STA and a wildcard STA identifier
according to an identifier of the AP and the identifier of at least one STA; and further,
if the STA determines that the control domain of the PPDU does not include the identifier
of the STA or the wildcard STA identifier, the STA configures an NAV according to
the duration information. In this process, only the control domain of the PPDU is
parsed, thereby improving data transmission efficiency.
[0033] The data domain may include an UL data domain and a DL data domain, and both the
UL data domain and the DL data domain are used to carry an MPDU.
[0034] A frame structure of a downlink MPDU carried on the data domain of the PPDU provided
in this embodiment of the present invention is shown in FIG. 13a to FIG. 13e. A difference
from the prior art is: A MAC header domain of the MPDU carried on the data domain
of the PPDU in this example of the present invention does not include a transmitter
address, a receiver address, or duration information; which may be specifically implemented
in two manners:
Manner 1 of generating the downlink MPDU: When the MPDU is formed at a MAC layer,
that is, the MAC header domain of the MPDU does not include the transmitter address,
the receiver address, or the duration information; in this case, the MAC header domain
of the MPDU carried on the data domain of the PPDU does not include the transmitter
address, the receiver address, or the duration information.
Manner 2 of generating the downlink MPDU: When the MPDU is formed at a MAC layer,
the MPDU is the same as that in the prior art, that is, the MAC header domain of the
MPDU includes the transmitter address, the receiver address, and the duration information;
when the PPDU is formed at a PHY layer, the transmitter address, the receiver address,
and the duration information in the MAC header domain of the MPDU are removed, and
then the MPDU whose MAC header domain does not include the transmitter address, the
receiver address, or the duration information is put in the data domain of the PPDU.
[0035] To make the objectives, technical solutions, and beneficial effects of the present
invention more comprehensible, the following further describes the present invention
in detail with reference to the accompanying drawings and embodiments. It should be
understood that the specific embodiments described herein are merely used to explain
the present invention but are not intended to limit the present invention.
[0036] The PPDU provided in this embodiment of the present invention may be applied to the
IEEE 802.11ax protocol; however, the method and the apparatus that are provided in
the embodiments of the present invention are not limited to the PPDU structure provided
in this embodiment of the present invention.
[0037] Based on the system architecture in FIG. 1, an embodiment of the present invention
provides a wireless local area network communications apparatus, where the wireless
local area network communications apparatus may be a component such as a chip, and
is used to transmit data in a wireless local area network. The communications apparatus
is disposed in an AP. The wireless local area network communications apparatus may
also be an AP, for example, a wireless access apparatus, a bridge, or a hotpot apparatus.
The wireless local area network communications apparatus may access a server or a
communications network.
[0038] As shown in FIG. 7, the wireless local area network communications apparatus may
include:
a processing unit 701, configured to generate a PPDU of a wireless local area network,
where the PPDU includes at least a PLCP header domain and a data domain, where the
PLCP header domain includes a preamble and a control domain, and the control domain
carries at least an identifier of the AP, an identifier of at least one STA, and duration
information; and
a transceiver unit 702, configured to send the generated PPDU.
[0039] The PPDU may be generated by a PHY layer entity, and an MPDU may be generated by
a MAC layer entity.
[0040] For a purpose of reducing redundant information, a MAC header domain of a downlink
MPDU carried on the data domain of the PPDU does not include a transmitter address,
a receiver address, or duration information, which may be implemented in the foregoing
two manners, and details are as follows:
Manner 1 of generating the downlink MPDU: The data domain of the PPDU generated by
the processing unit 701 carries a downlink MPDU whose MAC header domain does not include
a transmitter address, a receiver address, or duration information.
[0041] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0042] Manner 2 of generating the downlink MPDU: The data domain of the PPDU generated by
the processing unit 701 carries a downlink Medium Access Control protocol data unit
MPDU, where a MAC header domain of the downlink MPDU does not include a transmitter
address, a receiver address, or duration information.
[0043] Specifically, when the downlink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, the MAC header domain of the MPDU carried
on the data domain of the PPDU does not include the transmitter address, the receiver
address, or the duration information.
[0044] Preferably, the data domain of the PPDU further carries uplink data information,
and an uplink MPDU sent by a STA is received in the data domain according to resource
indication information in the PPDU. The uplink MPDU may be generated in two manners,
which are as follows:
Manner 1 of generating the uplink MPDU: The transceiver unit 702 receives an uplink
PPDU sent by a STA, where a data domain of the uplink PPDU carries an uplink MPDU
whose MAC header domain does not include a transmitter address, a receiver address,
or duration information.
[0045] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0046] Manner 2 of generating the uplink MPDU: The transceiver unit 702 receives an uplink
PPDU sent by a STA, where a data domain of the uplink PPDU carries an uplink MPDU,
where a MAC header domain of the uplink MPDU does not include a transmitter address,
a receiver address, or duration information.
[0047] Specifically, when the MPDU is formed at a MAC layer, that is, the MAC header domain
of the MPDU does not include the transmitter address, the receiver address, or the
duration information; in this case, an uplink MPDU whose MAC header domain does not
include the transmitter address, the receiver address, or the duration information
is sent.
[0048] Preferably, the MAC header domain of the uplink MPDU or the downlink MPDU carried
in the data domain includes at least a frame control field, where the frame control
field is used to indicate a type of the MPDU.
[0049] Preferably, when the type of the MPDU indicated by the frame control field is a management
frame or a data frame, the MAC header domain further includes at least an address
3 field and a sequence control field.
[0050] Preferably, when the type of the MPDU indicated by the frame control field is a quality
of service QoS data frame, the MAC header domain further includes at least a QoS control
field.
[0051] In specific implementation, the transceiver unit 702 is further configured to transmit
the data domain by using an OFDMA technology, where the MAC header domain of the uplink
MPDU or the downlink MPDU carried in the data domain further includes an OFDMA control
field.
[0052] It can be learned that the header domain of the MPDU does not include a transmitter
address, a receiver address, or duration information, which alleviates information
redundancy in a data transmission process, and improves transmission efficiency.
[0053] Preferably, the MAC header domain of the uplink MPDU or the downlink MPDU further
includes at least a frame control field, where the frame control field includes: an
indicator bit of a protocol version, an indicator bit of a type of a frame, or an
indicator bit of a subtype of a frame, and values of the foregoing three indicator
bits are newly added values.
[0054] Preferably, the processing unit 701 is specifically configured to generate N consecutive
PPDUs in an OFDMA transmission opportunity (English: Transmission Opportunity, TXOP
for short), where for an i
th frame in the N consecutive PPDUs, a time length value indicated by the duration information
of the control domain of the PLCP header domain is total duration from the beginning
of transmission of the i
th frame to the end of transmission of an N
th frame, and a value range of i is [1, N].
[0055] With the foregoing settings, a STA may keep silent in a process of transmitting N
consecutive PPDUs, and does not send data, thereby reducing channel interference.
[0056] In conclusion, in this embodiment of the present invention, a control domain of a
PLCP header domain in a PPDU carries identifier information of an AP, duration information,
and an identifier of at least one STA, so that a STA may obtain the identifier information
of the AP, the duration information, and the identifier of at least one STA by parsing
only the control domain of the PLCP header domain. Therefore, the STA may determine
whether the control domain of the PPDU includes an identifier of the STA and a wildcard
STA identifier according to an identifier of the AP and the identifier of at least
one STA; and further, if the STA determines that the control domain of the PPDU does
not include the identifier of the STA or the wildcard STA identifier, the STA configures
an NAV according to the duration information. In this process, only the control domain
of the PPDU is parsed, thereby improving data transmission efficiency.
[0057] Based on the same conception, an embodiment of the present invention provides a wireless
local area network communications apparatus used for transmitting data in a wireless
local area network. The communications apparatus is disposed in a STA, and may be
a wireless sensor, a wireless communications terminal, or a mobile terminal, such
as a mobile phone (also referred to as a "cellular" phone) supporting a Wi-Fi communication
function or a computer with a wireless communication function. For example, the communications
apparatus may be a portable, pocket-sized, handheld, computer built-in, wearable,
or in-vehicle wireless communications apparatus that supports the Wi-Fi communication
function. A STA changes communications data, such as voice or data, with a radio access
network.
[0058] As shown in FIG. 8, the wireless local area network communications apparatus may
include:
a transceiver unit 801, configured to receive a PPDU of a wireless local area network
sent by an AP, where the PPDU includes at least a PLCP header domain and a data domain,
where the PLCP header domain includes a preamble and a control domain, and the control
domain carries at least identifier information of the AP, an identifier of at least
one STA, and duration information; and
a processing unit 802, configured to obtain, by means of parsing, the identifier information
of the AP, the identifier of at least one STA, and the duration information in the
control domain of the PPDU.
[0059] The PPDU may be generated by a PIIY layer entity, and an MPDU may be generated by
a MAC layer entity.
[0060] For a purpose of reducing redundant information, in this example of the present invention,
a MAC header domain of a downlink MPDU carried on the data domain of the received
PPDU does not include a transmitter address, a receiver address, or duration information,
which may be implemented in the foregoing two manners, and details are as follows:
Manner 1 of generating the downlink MPDU: The data domain of the received PPDU carries
a downlink MPDU whose MAC header domain does not include a transmitter address, a
receiver address, or duration information.
[0061] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU. The processing unit obtains the
transmitter address and the receiver address in the MAC header domain of the downlink
MPDU according to an identifier of the AP and an identifier of a STA in the control
domain of the received PPDU.
[0062] Manner 2 of generating the downlink MPDU: The data domain of the received PPDU carries
a downlink Medium Access Control protocol data unit MPDU, where a MAC header domain
of the downlink MPDU does not include a transmitter address, a receiver address, or
duration information.
[0063] Specifically, when the downlink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, the MAC header domain of the MPDU carried
on the data domain of the PPDU does not include the transmitter address, the receiver
address, or the duration information. The processing unit obtains the transmitter
address and the receiver address of the downlink MPDU according to an identifier of
the AP and an identifier of a STA in the control domain of the received PPDU.
[0064] In specific implementation, the processing unit is further configured to: when it
is determined that the identifier that is obtained by means of parsing and that is
of the at least one STA in the PPDU does not include a wildcard identifier of a STA
in which the communications apparatus is located, configure, according to the duration
information obtained by means of parsing, an NAV of the STA in which the communications
apparatus is located. The at least one STA includes a STA associated with the AP in
the PPDU, and a wildcard STA. The identifier of the at least one STA is located in
resource indication information.
[0065] If the resource indication information does not include resource information configured
for the STA, and does not include wildcard resource indication information, a STA
for which no resource indication information resource is configured configures an
NAV of the STA according to the duration information, where the wildcard resource
indication information includes resource indication information of a group of STAs
or all STAs. Preferably, a wildcard identifier may be used in an HE-SIG 2 of the control
domain for indicating the wildcard resource indication information.
[0066] In specific implementation, if the STA determines, according to the identifier of
the AP, that the STA is not a STA associated with the AP, the STA determines whether
the resource indication information includes wildcard resource indication information
configured for all the STAs, and if the wildcard resource indication information is
not included, the STA configures an NAV of the STA according to the duration information.
[0067] If the STA determines, according to the identifier of the AP, that the STA is a STA
associated with the AP, the STA determines, according to the identifier of the AP
and resource indication information, whether the resource indication information includes
resource indication information configured for the STA. If the resource indication
information does not include the resource indication information configured for the
STA, and when it is further determined that the resource indication information does
not include wildcard resource indication information, the STA for which no resource
indication information is configured configures an NAV of the STA according to the
duration information, where the wildcard indication information includes resource
indication information of a group of STAs or all STAs, so as to ensure that no data
is sent within a time length of a duration message, thereby reducing channel interference.
[0068] When the STA is associated with the AP, and the resource indication information indicates
that the STA receives downlink data on a specified resource, the STA receives, on
the specified resource, data in a downlink data domain, and parses the received data.
[0069] Preferably, when the data domain of the PPDU further carries uplink data information,
the STA sends an uplink MPDU. The uplink MPDU may be generated in two manners, which
are as follows:
Manner 1 of generating the uplink MPDU: The processing unit generates an uplink PPDU,
where a data domain of the uplink PPDU carries an uplink MPDU whose MAC header domain
does not include a transmitter address, a receiver address, or duration information;
a transceiver unit sends the uplink PPDU.
[0070] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0071] Further, the tailored uplink MPDU sent by the STA may be further differentiated in
a scrambling manner, and scramble code used may be initialized by using an identifier
of the STA and/or the identifier of the AP. The AP receives the MPDU sent by the STA
in a specified time-frequency location in the resource indication information, and
performs descrambling on this section of data before parsing the MPDU. Scramble code
used is the same as that on a STA side.
[0072] For example, if the STA is associated with the AP, and the resource indication information
indicates that the STA sends uplink data on a specified resource, the STA removes
the receiver address (MAC address of the AP), the duration information, the transmitter
address (MAC address of the STA) in the MAC header domain of the uplink MPDU from
the MAC header domain of the uplink MPDU, and sends, in the data domain of the PPDU
according to the resource indication information, to the AP, an uplink MPDU whose
transmitter address, duration information, and receiver address are removed. When
the STA sends the uplink MPDU, the STA sends, on the specified resource, the uplink
MPDU according to resource indication information carried in the downlink PPDU; accordingly,
the AP receives, in the data domain, the uplink MPDU according to the resource indication
information.
[0073] Manner 2 of generating the uplink MPDU: The processing unit generates an uplink PPDU,
where a data domain of the uplink PPDU carries an uplink MPDU, where a MAC header
domain of the uplink MPDU does not include a transmitter address, a receiver address,
or duration information.
[0074] Specifically, when the uplink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, an uplink MPDU whose MAC header domain
does not include the transmitter address, the receiver address, or the duration information
is sent.
[0075] Further, for a purpose of reducing redundant information, when the STA sends uplink
data, data information in an attached PLCP header domain does not need to include
the identifier information of the AP or the duration information, and includes only
some data used for channel estimation and correlation detection.
[0076] According to different types of MPDUs or different transmission technologies used,
information included in the MAC header domain of the uplink MPDU or the downlink MPDU
in this embodiment of the present invention is also different.
[0077] Specifically, the MAC header domain of either the uplink MPDU or the downlink MPDU
includes at least a frame control field, where the frame control field is used to
indicate a type of the MPDU, as shown in FIG. 13a.
[0078] When the type of the MPDU indicated by the frame control field is a management frame
or a data frame, the MAC header domain may further include at least an address 3 field
and a sequence control field, as shown in FIG. 13c.
[0079] When the type of the MPDU indicated by the frame control field is a QoS data frame,
the MAC header domain may further include at least a QoS control field, as shown in
FIG. 13d.
[0080] The data domain of the generated PPDU is sent by using an orthogonal frequency division
multiple access OFDMA technology, where the MAC header domain of the uplink MPDU or
the downlink MPDU carried in the data domain further includes an OFDMA control field,
as shown in FIG. 13e.
[0081] It can be learned that when the STA sends uplink data, redundant data is reduced,
and transmission efficiency is improved.
[0082] In conclusion, in this embodiment of the present invention, a control domain of a
PLCP header domain in a PPDU carries identifier information of an AP, duration information,
and an identifier of at least one STA, so that a STA may obtain the identifier information
of the AP, the duration information, and the identifier of at least one STA by parsing
only the control domain of the PLCP header domain. Therefore, the STA may determine
whether the control domain of the PPDU includes an identifier of the STA and a wildcard
STA identifier according to an identifier of the AP and the identifier of at least
one STA; and further, if the STA determines that the control domain of the PPDU does
not include the identifier of the STA or the wildcard STA identifier, the STA configures
an NAV according to the duration information. In this process, only the control domain
of the PPDU is parsed, thereby improving data transmission efficiency. The wildcard
STA identifier includes identifiers of a group of STAs or all STAs.
[0083] Based on the same conception, an embodiment of the present invention provides a wireless
local area network communications apparatus, where the wireless local area network
communications apparatus may be a component such as a chip, and is used to transmit
data in a wireless local area network. The communications apparatus is disposed in
an AP. The wireless local area network communications apparatus may also be an AP,
for example, a wireless access apparatus, a bridge, or a hotpot apparatus. The wireless
local area network communications apparatus may access a server or a communications
network.
[0084] As shown in FIG. 9, the wireless local area network communications apparatus includes
a processor 901, a transceiver 902, and a memory 903.
[0085] The processor 901 is configured to generate a PPDU of a wireless local area network,
where the PPDU includes at least a PLCP header domain and a data domain, where the
PLCP header domain includes a preamble and a control domain, and the control domain
carries at least an identifier of the AP, an identifier of at least one STA, and duration
information.
[0086] The transceiver 902 is configured to send the generated PPDU.
[0087] The memory 903 is configured to store an MPDU and the PPDU. The memory 903 may also
store code used by the processor 901 to execute the foregoing process.
[0088] The PPDU may be generated by a PHY layer entity, and the MPDU may be generated by
a MAC layer entity.
[0089] For a purpose of reducing redundant information, a MAC header domain of a downlink
MPDU carried on the data domain of the PPDU does not include a transmitter address,
a receiver address, or duration information, which may be implemented in the foregoing
two manners, and details are as follows:
[0090] Manner 1 of generating the downlink MPDU: The data domain of the PPDU generated by
the processor 901 carries a downlink MPDU whose MAC header domain does not include
a transmitter address, a receiver address, or duration information.
[0091] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0092] Manner 2 of generating the downlink MPDU: The data domain of the PPDU generated by
the processor 901 carries a downlink MPDU, where a MAC header domain of the downlink
MPDU does not include a transmitter address, a receiver address, or duration information.
[0093] Specifically, when the downlink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, the MAC header domain of the MPDU carried
on the data domain of the PPDU does not include the transmitter address, the receiver
address, or the duration information.
[0094] Preferably, the data domain of the PPDU further carries uplink data information,
and an uplink MPDU sent by a STA is received in the data domain according to resource
indication information in the PPDU. The uplink MPDU may be generated in two manners,
which are as follows:
[0095] Manner 1 of generating the uplink MPDU: The transceiver 902 receives an uplink PPDU
sent by a STA, where a data domain of the uplink PPDU carries an uplink MPDU whose
MAC header domain does not include a transmitter address, a receiver address, or duration
information.
[0096] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0097] Manner 2 of generating the uplink MPDU: The transceiver 902 receives an uplink PPDU
sent by a STA, where a data domain of the uplink PPDU carries an uplink MPDU, where
a MAC header domain of the uplink MPDU does not include a transmitter address, a receiver
address, or duration information.
[0098] Specifically, when the uplink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, an uplink MPDU whose MAC header domain
does not include the transmitter address, the receiver address, or the duration information
is sent.
[0099] In specific implementation, the transceiver 902 is further configured to transmit
the data domain by using an OFDMA technology, where the MAC header domain of the uplink
MPDU or the downlink MPDU carried in the data domain further includes an OFDMA control
field.
[0100] Preferably, the MAC header domain of the uplink MPDU or the downlink MPDU carried
in the data domain includes at least a frame control field, where the frame control
field is used to indicate a type of the MPDU.
[0101] Preferably, when the type of the MPDU indicated by the frame control field is a management
frame or a data frame, the MAC header domain further includes at least an address
3 field and a sequence control field.
[0102] Preferably, when the type of the MPDU indicated by the frame control field is a quality
of service QoS data frame, the MAC header domain further includes at least a QoS control
field.
[0103] Preferably, the data domain of the generated PPDU is sent by using an orthogonal
frequency division multiple access OFDMA technology, where the MAC header domain of
the uplink MPDU or the downlink MPDU carried in the data domain further includes an
OFDMA control field.
[0104] It can be learned that the header domain of the MPDU does not include a transmitter
address, a receiver address, or duration information, which alleviates information
redundancy in a data transmission process, and improves transmission efficiency.
[0105] Preferably, the MAC header domain of the uplink MPDU or the downlink MPDU further
includes at least a frame control field, where the frame control field includes: an
indicator bit of a protocol version, an indicator bit of a type of a frame, or an
indicator bit of a subtype of a frame, and values of the foregoing three indicator
bits are newly added values.
[0106] Preferably, the processor 901 is specifically configured to generate N consecutive
PPDUs in an OFDMA transmission opportunity (English: Transmission Opportunity, TXOP
for short), where for an i
th frame in the N consecutive PPDUs, a time length value indicated by the duration information
of the control domain of the PLCP header domain is total duration from the beginning
of transmission of the i
th frame to the end of transmission of an N
th frame, and a value range of i is [1, N].
[0107] With the foregoing settings, a STA may keep silent in a process of transmitting N
consecutive PPDUs, and does not send data, thereby reducing channel interference.
[0108] In conclusion, in this embodiment of the present invention, a control domain of a
PLCP header domain in a PPDU carries identifier information of an AP, duration information,
and an identifier of at least one STA, so that a STA may obtain the identifier information
of the AP, the duration information, and the identifier of at least one STA by parsing
only the control domain of the PLCP header domain. Therefore, the STA may determine
whether the control domain of the PPDU includes an identifier of the STA and a wildcard
STA identifier according to an identifier of the AP and the identifier of at least
one STA; and further, if the STA determines that the control domain of the PPDU does
not include the identifier of the STA or the wildcard STA identifier, the STA configures
an NAV according to the duration information. In this process, only the control domain
of the PPDU is parsed, thereby improving data transmission efficiency.
[0109] Based on the same conception, an embodiment of the present invention provides a wireless
local area network communications apparatus used for transmitting data in a wireless
local area network. A STA apparatus may be a wireless sensor, a wireless communications
terminal, or a mobile terminal, for example, a mobile phone (or referred to as a "cellular"
phone) supporting a Wi-Fi communication function or a computer with a wireless communication
function. For example, the STA apparatus may be a portable, pocket-sized, handheld,
computer built-in, wearable, or in-vehicle wireless communications apparatus that
supports the Wi-Fi communication function. The STA apparatus changes communications
data, such as voice or data, with a radio access network.
[0110] As shown in FIG. 10, the wireless local area network communications apparatus includes
a transceiver 1001, a processor 1002, and a memory 1003.
[0111] The transceiver 1001 is configured to receive a PPDU of a wireless local area network
sent by an AP, where the PPDU includes at least a PLCP header domain and a data domain,
where the PLCP header domain includes a preamble and a control domain, and the control
domain carries at least identifier information of the AP, an identifier of at least
one STA, and duration information.
[0112] The processor 1002 is configured to obtain, by means of parsing, the identifier information
of the AP, the identifier of at least one STA, and the duration information in the
control domain of the PPDU.
[0113] The memory 1003 is configured to store an MPDU and the PPDU. The memory 1003 may
also store code used by the processor 1002 to execute the foregoing process.
[0114] The PPDU may be generated by a PHY layer entity, and the MPDU may be generated by
a MAC layer entity.
[0115] For a purpose of reducing redundant information, in this example of the present invention,
a MAC header domain of a downlink MPDU carried on the data domain of the received
PPDU does not include a transmitter address, a receiver address, or duration information,
which may be implemented in the foregoing two manners, and details are as follows:
Manner 1 of generating the downlink MPDU: The data domain of the received PPDU carries
a downlink MPDU whose MAC header domain does not include a transmitter address, a
receiver address, or duration information.
[0116] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU. The processing unit obtains the
transmitter address and the receiver address in the MAC header domain of the downlink
MPDU according to an identifier of the AP and an identifier of a STA in the control
domain of the received PPDU.
[0117] Manner 2 of generating the downlink MPDU: The data domain of the received PPDU carries
a downlink Medium Access Control protocol data unit MPDU, where a MAC header domain
of the downlink MPDU does not include a transmitter address, a receiver address, or
duration information.
[0118] Specifically, when the downlink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, the MAC header domain of the MPDU carried
on the data domain of the PPDU does not include the transmitter address, the receiver
address, or the duration information. The processing unit obtains the transmitter
address and the receiver address of the downlink MPDU according to an identifier of
the AP and an identifier of a STA in the control domain of the received PPDU.
[0119] In specific implementation, the processing unit is further configured to: when it
is determined that the identifier that is obtained by means of parsing and that is
of the at least one STA in the PPDU does not include a wildcard identifier of a STA
in which the communications apparatus is located, configure, according to the duration
information obtained by means of parsing, an NAV of the STA in which the communications
apparatus is located. The at least one STA includes a STA associated with the AP in
the PPDU, and a wildcard STA. The identifier of the at least one STA is located in
resource indication information.
[0120] If the resource indication information does not include resource information configured
for the STA, and does not include wildcard resource indication information, a STA
for which no resource indication information resource is configured configures an
NAV of the STA according to the duration information, where the wildcard resource
indication information includes resource indication information of a group of STAs
or all STAs. Preferably, a wildcard identifier may be used in an HE-SIG 2 of the control
domain for indicating the wildcard resource indication information.
[0121] In specific implementation, if the STA determines, according to the identifier of
the AP, that the STA is not a STA associated with the AP, the STA determines whether
the resource indication information includes wildcard resource indication information
configured for all the STAs, and if the wildcard resource indication information is
not included, the STA configures an NAV of the STA according to the duration information.
[0122] If the STA determines, according to the identifier of the AP, that the STA is a STA
associated with the AP, the STA determines, according to the identifier of the AP
and the resource indication information, whether the resource indication information
includes resource indication information configured for the STA. If the resource indication
information does not include the resource indication information configured for the
STA, and when it is further determined that the resource indication information does
not include the wildcard resource indication information, the STA for which no resource
indication information is configured configures an NAV of the STA according to the
duration information, where the wildcard indication information includes resource
indication information of a group of STAs or all STAs, so as to ensure that no data
is sent within a time length of a duration message, thereby reducing channel interference.
[0123] When the STA is associated with the AP, and the resource indication information indicates
that the STA receives downlink data on a specified resource, the STA receives, on
the specified resource, data in a downlink data domain, and parses the received data.
[0124] Preferably, when the data domain of the PPDU further carries uplink data information,
the STA sends an uplink MPDU. The uplink MPDU may be generated in two manners, which
are as follows:
Manner 1 of generating the uplink MPDU: The processing unit generates an uplink PPDU,
where a data domain of the uplink PPDU carries an uplink MPDU whose MAC header domain
does not include a transmitter address, a receiver address, or duration information;
and a transceiver unit sends the uplink PPDU.
[0125] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0126] Further, the tailored uplink MPDU sent by the STA may be further differentiated in
a scrambling manner, and scramble code used may be initialized by using an identifier
of the STA and/or an identifier of the AP. The AP receives the MPDU sent by the STA
in a specified time-frequency location in the resource indication information, and
performs descrambling on this section of data before parsing the MPDU. Scramble code
used is the same as that on a STA side.
[0127] For example, if the STA is associated with the AP, and the resource indication information
indicates that the STA sends uplink data on a specified resource, the STA removes
the receiver address (English: MAC address of the AP), the duration information, and
the transmitter address (English: MAC address of the STA) in the MAC header domain
of the uplink MPDU from the MAC header domain of the uplink MPDU, and sends, in the
data domain of the PPDU according to the resource indication information, to the AP,
an uplink MPDU whose transmitter address, duration information, and receiver address
are removed. When the STA sends the uplink MPDU, the STA sends, on the specified resource,
the uplink MPDU according to resource indication information carried in the downlink
PPDU; accordingly, the AP receives, in the data domain, the uplink MPDU according
to the resource indication information.
[0128] Manner 2 of generating the uplink MPDU: The processing unit generates an uplink PPDU,
where a data domain of the uplink PPDU carries an uplink MPDU, and a MAC header domain
of the uplink MPDU does not include a transmitter address, a receiver address, or
duration information.
[0129] Specifically, when the uplink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, an uplink MPDU whose MAC header domain
does not include the transmitter address, the receiver address, or the duration information
is sent.
[0130] Further, for a purpose of reducing redundant information, when the STA sends uplink
data, data information in an attached PLCP header domain does not need to include
the identifier information of the AP or the duration information, and includes only
some data used for channel estimation and correlation detection.
[0131] According to different types of MPDUs or different transmission technologies used,
information included in the MAC header domain of the uplink MPDU or the downlink MPDU
in this embodiment of the present invention is also different.
[0132] Specifically, the MAC header domain of either the uplink MPDU or the downlink MPDU
includes at least a frame control field, where the frame control field is used to
indicate a type of the MPDU, as shown in FIG. 13a.
[0133] When the type of the MPDU indicated by the frame control field is a management frame
or a data frame, the MAC header domain may further include at least an address 3 field
and a sequence control field, as shown in FIG. 13c.
[0134] When the type of the MPDU indicated by the frame control field is a QoS data frame,
the MAC header domain may further include at least a QoS control field, as shown in
FIG. 13d.
[0135] The data domain of the generated PPDU is sent by using an orthogonal frequency division
multiple access OFDMA technology, where the MAC header domain of the uplink MPDU or
the downlink MPDU carried in the data domain further includes an OFDMA control field,
as shown in FIG. 13e.
[0136] It can be learned that when the STA sends uplink data, redundant data is reduced,
and transmission efficiency is improved.
[0137] In conclusion, in this embodiment of the present invention, a control domain of a
PLCP header domain in a PPDU carries identifier information of an AP, duration information,
and an identifier of at least one STA, so that a STA may obtain the identifier information
of the AP, the duration information, and the identifier of at least one STA by parsing
only the control domain of the PLCP header domain. Therefore, the STA may determine
whether the control domain of the PPDU includes an identifier of the STA and a wildcard
STA identifier according to an identifier of the AP and the identifier of at least
one STA; and further, if the STA determines that the control domain of the PPDU does
not include the identifier of the STA or the wildcard STA identifier, the STA configures
an NAV according to the duration information. In this process, only the control domain
of the PPDU is parsed, thereby improving data transmission efficiency.
[0138] Based on the same conception, an embodiment of the present invention provides a wireless
local area network data transmission method that is applicable to an AP side, and
a process may be implemented by using the apparatus shown in the foregoing FIG. 7
or FIG. 9. As shown in FIG. 11, which is a schematic diagram of a data transmission
process according to an embodiment of the present invention, the process includes
the following steps:
Step 1101: Generate a PPDU of a wireless local area network, where the PPDU includes
at least a PLCP header domain and a data domain, where the PLCP header domain includes
a preamble and a control domain, and the control domain carries at least an identifier
of an AP, an identifier of at least one STA, and duration information.
Step 1102: Send the generated PPDU.
[0139] A format of an OFDMA PPDU constructed in step 1101 is shown in FIG. 6, which is described
below in detail.
[0140] Preferably, in this embodiment of the present invention, the AP adds the preamble
and the control domain to the PLCP header domain of the PPDU.
[0141] The preamble is an L-Pre used for performing time-frequency synchronization on the
STA and the AP; the control domain includes an HE-SIG 1 and an HE-SIG 2.
[0142] For a purpose of reducing redundant information, a MAC header domain of a downlink
MPDU carried on the data domain of the PPDU does not include a transmitter address,
a receiver address, or duration information, which may be implemented in the foregoing
two manners, and details are as follows:
Manner 1 of generating the downlink MPDU: The data domain of the generated PPDU carries
a downlink MPDU whose MAC header domain does not include a transmitter address, a
receiver address, or duration information.
[0143] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0144] Manner 2 of generating the downlink MPDU: The data domain of the generated PPDU carries
a downlink MPDU, where a MAC header domain of the downlink MPDU does not include a
transmitter address, a receiver address, or duration information.
[0145] Specifically, when the downlink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, the MAC header domain of the MPDU carried
on the data domain of the PPDU does not include the transmitter address, the receiver
address, or the duration information.
[0146] In specific implementation, identifier information of the AP and the duration information
are added to the PLCP header domain, and the MAC header domain of the downlink MPDU
does not include the transmitter address, the duration information, or the receiver
address; where the transmitter address is an address 2 in the MAC header domain of
the MPDU, and the receiver address is an address 1 in the MAC header domain of the
MPDU.
[0147] In the method provided in this embodiment of the present invention, an AP sends,
in a broadcast manner, a PPDU to all STAs within a coverage area of an AP network,
including STAs associated or not associated with the AP. After parsing the preamble,
the STA obtains identifier information of the AP and the duration information by sequentially
parsing the control domain; the STA determines, according to the identifier information
of the AP, identifier information of the STA, and resource indication information,
that no resource indication information configured for the STA is included, that is,
subsequent data of the PPDU does not include an MPDU belonging to the STA or an uplink
transmission resource that is not scheduled by the STA, and does not include wildcard
resource indication information. A STA for which no resource indication information
is configured configures, according to the duration information, an NAV of the STA,
where the wildcard resource indication information includes resource indication information
of a group of STAs or all the STAs, so as to ensure that no data is sent within a
time length of a duration message, thereby reducing channel interference.
[0148] It can be learned that the identifier information of the AP and the duration information
are added to the PLCP header domain, so that a STA not associated with the AP may
configure an NAV of the STA according to the duration information without parsing
subsequent transmission data MPDU, thereby improving data transmission efficiency.
In addition, the MPDU does not include the transmitter address or the duration information,
which avoids repeated transmission of the identifier information of the AP and the
duration information, alleviates information redundancy in a data transmission process,
and improves transmission efficiency.
[0149] Specifically, the identifier information of the AP may be added to an HE-SIG 1 or
an HE-SIG 2 of the control domain, and the duration information may be added to the
HE-SIG 1 or the HE-SIG 2 of the control domain.
[0150] When the identifier information of the AP is parsed out by the STA, the STA determines
whether the STA is associated with the AP; after the resource indication information
is parsed out, the STA determines whether resource indication information of the STA
exists, and if resource indication information configured for the STA is not included,
a STA for which no resource indication information is configured configures an NAV
of the STA according to the duration information.
[0151] Preferably, resource indication information that is still carried in the control
domain is located in the HE-SIG 2 of the control domain. Specifically, the resource
indication information includes: allocation information of uplink and downlink OFDMA
time-frequency resource blocks, identifier information of the scheduled STA, transmission
signaling corresponding to the STA associated with the scheduled AP, and some other
transmission parameter configuration, such as a quantity of spatial flows.
[0152] The STA may learn, according to the resource indication information, whether subsequent
data load includes data belonging to the STA, so as to determine whether to parse
the MPDU. If the resource indication information indicates that the STA does not need
to transmit data, the STA configures an NAV of the STA according to the duration information,
and no data is sent within a period of time specified in the duration information,
thereby reducing channel interference. If the resource indication information indicates
that the STA needs to receive downlink data on a time-frequency resource, or needs
to send uplink data on a time-frequency resource, the STA continues to parse the MPDU,
and transmits data with the AP.
[0153] It can be learned that because the resource indication information includes the identifier
information of the STA, the MPDU may not include a MAC address of the STA, thereby
reducing redundant data in the MPDU, and improving transmission efficiency.
[0154] Specifically, a data domain following the HE-SIG 1 or the HE-SIG 2 further includes
a training sequence used by the STA to perform channel estimation and coherent detection.
[0155] Preferably, the duration information is specifically configured to generate N consecutive
PPDUs in an OFDMA TXOP, where for an i
th frame in the N consecutive PPDUs, a time length value indicated by the duration information
of the control domain of the PLCP header domain is total duration from the beginning
of transmission of the i
th frame to the end of transmission of an N
th frame, and a value range of i is [1, N].
[0156] For example, as shown in FIG. 12, it is assumed that there are three consecutive
OFDMA PPDUs in an OFDMA TXOP. A time length value indicated by duration information
of a PPDU of the first frame is total duration from the beginning of transmission
of the first frame to the end of transmission of the third frame, a time length value
indicated by duration information of a PPDU of the second frame is total duration
from the beginning of transmission of the second frame to the end of transmission
of the third frame, and a time length value indicated by duration information of a
PPDU of the third frame is total duration from the beginning of transmission of the
third frame to the end of transmission of the third frame.
[0157] With the foregoing settings, a STA may keep silent in a process of transmitting N
consecutive PPDUs, and does not send data, thereby reducing channel interference.
[0158] In specific implementation, the MAC header domain of the uplink MPDU or the downlink
MPDU further includes at least a frame control field. The frame control field is used
to indicate a type of the MPDU, as shown in FIG. 13a. Types of an MPDU include a control
frame, a management frame, and a data frame. A control frame in a WLAN is, for example,
request to send (English: request to send, RTS for short), clear to send (English:
clear to send, CTS for short), or acknowledgement (English: Acknowledgement, ACK for
short).
[0159] Preferably, when the type of the MPDU indicated by the frame control field is a management
frame or a data frame, the MAC header domain further includes at least an address
3 field and a sequence control field, as shown in FIG. 13c. For content carried in
the address 3 field, refer to an existing 802.11 protocol.
[0160] Specifically, the management frame or the data frame has many subtype frame structures.
When the type of the MPDU indicated by the frame control field is either the management
frame or the data frame, or any one of subtype frames in the management frame or the
data frame, the MAC header domain further includes at least the address 3 field and
the sequence control field.
[0161] Preferably, when the type of the MPDU indicated by the frame control field is a QoS
data frame, the MAC header domain further includes at least a QoS control field, as
shown in FIG. 13d.
[0162] In specific implementation, the data domain of the generated PPDU is sent by using
an orthogonal frequency division multiple access OFDMA technology, where the MAC header
domain of the uplink MPDU or the downlink MPDU carried in the data domain further
includes an OFDMA control field, as shown in FIG. 13e.
[0163] For some frames whose transmission efficiency is not high but require integrity of
addressing, for example, a beacon frame, or a probe response frame, a complete MPDU
is still added to the data domain of the PPDU in OFDMA transmission.
[0164] In specific implementation, the MAC header domain of the uplink MPDU or the downlink
MPDU further includes at least a frame control field, where the frame control field
includes: an indicator bit of a protocol version, an indicator bit of a type of a
frame, or an indicator bit of a subtype of a frame, and values of the foregoing three
indicator bits are newly added values.
[0165] Specifically, in the method of this embodiment of the present invention, the indicator
bit of a protocol version in the frame control field of the MAC header domain may
be set to a value different from a default value. The existing 802.11 protocol specifies
that the default value of the indicator bit of the protocol version in the frame control
field of the MPDU is "00'; in this case, a structure of the MPDU is shown in FIG.
4. When data carried in the MPDU is reduced, the indicator bit of a protocol version
in the frame control field of the MAC header domain may be set to a value different
from the default value, for example, "01", "10", or "11"; in this case, a structure
of the MPDU is shown in FIG. 13a, FIG. 13b, FIG. 13c, and FIG. 13d.
[0166] Specifically, in the method of this embodiment of the present invention, the indicator
bit for indicating a type of a frame in a frame control field of the MAC header domain
may further be set to a newly added value, or the indicator bit for indicating a subtype
of a frame in a frame control field of the MAC header domain may be set to a newly
added value. That is, some values of indicator bits are newly added for indicating
the control frame, the management frame, or the data frame, and some values of indicator
bits are newly added for indicating a subtype of each frame type.
[0167] For example, FIG. 13b is a data domain structure in a frame control domain for indicating
a type of a frame and a subtype of a frame, that is, a type of a sub-frame.
[0168] When an indicator bit of a frame type is "00", it indicates that the MPDU is a management
frame, and common values for indicating a subtype frame of a management frame are
"0000-1110"; in this case, in the method of this embodiment of the present invention,
an indicator bit of a type of a sub-frame may be set to "1111".
[0169] When an indicator bit of a frame type is "01", it indicates that the MPDU is a control
frame, and common values for indicating a subtype frame of a control frame are "0111-1111";
in this case, in the method of this embodiment of the present invention, an indicator
bit of a type of a sub-frame may be set to a value in a range of "0000-0110".
[0170] When the MPDU is a data frame, because all subtypes under an indicator bit "10" of
a frame type are used, in the method of this embodiment of the present invention,
the data frame may be indicated by setting an indicator bit of a frame type as "11",
and setting a subtype to a meaningful value.
[0171] In step 1102, the AP may send, in a broadcast manner, the preamble to all STAs within
a coverage area of an AP network, and all the STAs perform time-frequency synchronization
with the AP.
[0172] The AP may send, in a broadcast manner, the control domain to all STAs within a coverage
area of an AP network, and all the STAs parse data in the control domain to obtain
identifier information of the AP, duration information, and resource indication information
configured for the STA.
[0173] Preferably, the data domain of the PPDU further carries uplink data information,
and an uplink MPDU sent by a STA is received in the data domain according to resource
indication information in the PPDU. The uplink MPDU may be generated in two manners,
which are as follows:
Manner 1 of generating the uplink MPDU: receiving an uplink PPDU sent by a STA, where
a data domain of the uplink PPDU carries an uplink MPDU whose MAC header domain does
not include a transmitter address, a receiver address, or duration information.
[0174] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0175] Manner 2 of generating the uplink MPDU: receiving an uplink PPDU sent by a STA, where
a data domain of the uplink PPDU carries an uplink MPDU, where a MAC header domain
of the uplink MPDU does not include a transmitter address, a receiver address, or
duration information.
[0176] Specifically, when the uplink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, an uplink MPDU whose MAC header domain
does not include the transmitter address, the receiver address, or the duration information
is sent.
[0177] If the STA is associated with the AP, and the resource indication information indicates
that the STA sends uplink data on a specified resource, the STA sends the uplink MPDU,
that is, the STA sends, in the data domain of the PPDU according to the resource indication
information, the uplink MPDU that does not include the transmitter address, the duration
information, or the receiver address to the AP, and the STA sends, on the specified
resource, the uplink MPDU; the AP receives, in the data domain according to the resource
indication information, the uplink MPDU sent by the STA.
[0178] Further, when the STA sends uplink data, data information in an attached PLCP header
domain may not include identifier information of the AP and duration information,
and may include only some data used for channel estimation and coherent detection,
thereby reducing redundant data and improving transmission efficiency.
[0179] In conclusion, in this embodiment of the present invention, a control domain of a
PLCP header domain in a PPDU carries identifier information of an AP, duration information,
and an identifier of at least one STA, so that a STA may obtain the identifier information
of the AP, the duration information, and the identifier of at least one STA by parsing
only the control domain of the PLCP header domain. Therefore, the STA may determine
whether the control domain of the PPDU includes an identifier of the STA and a wildcard
STA identifier according to an identifier of the AP and the identifier of at least
one STA; and further, if the STA determines that the control domain of the PPDU does
not include the identifier of the STA or the wildcard STA identifier, the STA configures
an NAV according to the duration information. In this process, only the control domain
of the PPDU is parsed, thereby improving data transmission efficiency.
[0180] Based on the same conception, an embodiment of the present invention provides a process
of a data transmission method. The method is applicable to a STA side, and the process
may be implemented by using the apparatus shown in FIG. 8 or FIG. 10. As shown in
FIG. 14, which is a schematic diagram of a data transmission process according to
an embodiment of the present invention, the process includes the following steps:
[0181] Step 1401: Receive a PPDU of a wireless local area network sent by an AP, where the
PPDU includes at least a PLCP header domain and a data domain, where the PLCP header
domain includes a preamble and a control domain, and the control domain carries at
least identifier information of the AP, an identifier of at least one STA, and duration
information.
[0182] Step 1402: Obtain, by means of parsing, the identifier information of the AP, the
identifier of at least one station STA, and the duration information in the control
domain of the PPDU. In specific implementation, resource indication information configured
for the STA is parsed, and data transmission with the AP is performed by using the
data domain of the PPDU according to the resource indication information.
[0183] A format of an OFDMA PPDU constructed in step 1401 and step 1402 is shown in FIG.
6, which is described below in detail.
[0184] In specific implementation, when it is determined that the identifier that is obtained
by means of parsing and that is of the at least one STA in the PPDU does not include
an identifier of the STA, and does not include a wildcard STA identifier, an NAV of
the STA is configured according to the duration information obtained by means of parsing.
As mentioned above, the AP may send, in a broadcast manner, the PPDU to all STAs within
a coverage area of an AP network. After parsing the preamble of the PPDU, the STA
may obtain by sequentially parsing the control domain, the identifier information
of the AP, the duration information and the resource indication information, and then
the STA for which no resource indication information is configured configures an NAV
of the STA according to the duration information, so as to ensure that no data is
sent within a time length of a duration message, thereby reducing channel interference.
[0185] It can be learned that if the identifier information of the AP and the duration information
are added to the PLCP header domain, a STA for which no resource indication information
is configured may configure an NAV of the STA according to the duration information
without parsing subsequent transmission data MPDU, thereby improving data transmission
efficiency.
[0186] As mentioned above, in the PLCP header domain of the PPDU, the identifier information
of the AP may be added to an HE-SIG 1 or an HE-SIG 2 of the control domain, and the
duration information may be added to the HE-SIG 1 or the HE-SIG 2 of the control domain.
[0187] When the identifier information of the AP is parsed out by the STA, the STA determines
whether the STA is associated with the AP; after the resource indication information
is parsed out, the STA determines whether resource indication information of the STA
exists, and if resource indication information configured for the STA is not included,
a STA for which no resource indication information is configured configures an NAV
of the STA according to the duration information.
[0188] Preferably, resource indication information that is still carried in the control
domain is located in the HE-SIG 2 of the control domain. Specifically, the resource
indication information includes: allocation information of uplink and downlink OFDMA
time-frequency resource blocks, identifier information of the scheduled STA, transmission
signaling corresponding to the STA associated with the scheduled AP, and some other
transmission parameter configuration, such as a quantity of spatial flows.
[0189] The STA may learn, according to the resource indication information, whether subsequent
data load includes data belonging to the STA, so as to determine whether to parse
the MPDU. If the resource indication information indicates that the STA does not need
to transmit data, the STA configures an NAV of the STA according to the duration information,
and no data is sent within a period of time specified in the duration information,
thereby reducing channel interference. If the resource indication information indicates
that the STA needs to receive downlink data on a time-frequency resource, or needs
to send uplink data on a time-frequency resource, the STA continues to parse the MPDU,
and transmits data with the AP.
[0190] If the STA is not associated with the AP, and the resource indication information
does not include wildcard resource indication information, the STA configures an NAV
of the STA according to the duration information, where the wildcard resource information
includes resource indication information of a group of STAs or all STAs, so as to
ensure that no data is sent within a time length of a duration message, thereby reducing
channel interference.
[0191] If the STA is associated with the AP, but the resource indication information does
not include resource information configured for the STA, and when it is further determined
that the resource indication information does not include wildcard resource indication
information, a STA for which no resource indication information resource is configured
configures an NAV of the STA according to the duration information, where the wildcard
resource indication information includes resource indication information of a group
of STAs or all the STAs, so as to ensure that no data is sent within a time length
of a duration message, thereby reducing channel interference.
[0192] If the STA is associated with the AP, and the resource indication information indicates
that the STA receives downlink data on a specified resource, the STA receives, on
the specified resource, data in a downlink data domain, and parses the received data.
[0193] For a purpose of reducing redundant information, in this example of the present invention,
a MAC header domain of a downlink MPDU carried on the data domain of the received
PPDU does not include a transmitter address, a receiver address, or duration information,
which may be implemented in the foregoing two manners, and details are as follows:
Manner 1 of generating the downlink MPDU: The data domain of the received PPDU carries
a downlink Medium Access Control protocol data unit MPDU whose MAC header domain does
not include a transmitter address, a receiver address, or duration information; the
transmitter address and the receiver address in the MAC header domain of the downlink
MPDU are obtained according to an identifier of the AP and an identifier of the STA
in the control domain of the received PPDU.
[0194] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0195] Manner 2 of generating the downlink MPDU: The data domain of the received MPDU carries
a downlink MPDU, where a MAC header domain of the downlink MPDU does not include a
transmitter address, a receiver address, or duration information; the transmitter
address and the receiver address of the downlink MPDU are obtained according to an
identifier of the AP and an identifier of the STA in the control domain of the received
PPDU.
[0196] Specifically, when the downlink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, the MAC header domain of the MPDU carried
on the data domain of the PPDU does not include the transmitter address, the receiver
address, or the duration information.
[0197] If the STA is associated with the AP, and the resource indication information indicates
that the STA sends uplink data on a specified resource, the STA sends, in the data
domain of the PPDU, an uplink MPDU to the AP according to the resource indication
information; the AP receives, in the data domain according to the resource indication
information, the uplink MPDU sent by the STA.
[0198] Preferably, when the data domain of the PPDU further carries uplink data information,
the STA sends an uplink MPDU. The uplink MPDU may be generated in two manners, which
are as follows:
Manner 1 of generating the uplink MPDU: generating an uplink PPDU, where a data domain
of the uplink PPDU carries an uplink MPDU whose MAC header domain does not include
a transmitter address, a receiver address, or duration information; and the transceiver
unit is further configured to send the uplink PPDU.
[0199] Specifically, when the MPDU is formed at a MAC layer, the MPDU is the same as that
in the prior art, that is, the MAC header domain of the MPDU includes the transmitter
address, the receiver address, and the duration information; when the PPDU is formed
at a PHY layer, the transmitter address, the receiver address, and the duration information
in the MAC header domain of the MPDU are removed, and then the MPDU whose MAC header
domain does not include the transmitter address, the receiver address, or the duration
information is put in the data domain of the PPDU.
[0200] Further, the tailored uplink MPDU sent by the STA may be further differentiated in
a scrambling manner, and scramble code used may be initialized by using an identifier
of the STA and/or an identifier of the AP. The AP receives the MPDU sent by the STA
in a specified time-frequency location in the resource indication information, and
performs descrambling on this section of data before parsing the MPDU. Scramble code
used is the same as that on a STA side.
[0201] Manner 2 of generating the uplink MPDU: generating an uplink PPDU, where a data domain
of the uplink PPDU carries an uplink MPDU, where a MAC header domain of the uplink
MPDU does not include a transmitter address, a receiver address, or duration information.
[0202] Specifically, when the uplink MPDU is formed at a MAC layer, that is, the MAC header
domain of the MPDU does not include the transmitter address, the receiver address,
or the duration information; in this case, an uplink MPDU whose MAC header domain
does not include the transmitter address, the receiver address, or the duration information
is sent.
[0203] In this example of the present invention, the MPDU does not include the transmitter
address, the duration information, or the receiver address, which reduces data carried
on the MPDU, reduces redundant data, and improves transmission efficiency.
[0204] Specifically, the MAC header domain of either the uplink MPDU or the downlink MPDU
includes at least a frame control field, where the frame control field is used to
indicate a type of the uplink MPDU, as shown in FIG. 13a.
[0205] When the type of the uplink MPDU indicated by the frame control field is a management
frame or a data frame, the MAC header domain further includes at least an address
3 field and a sequence control field, as shown in FIG. 13c.
[0206] When the type of the uplink MPDU indicated by the frame control field is a QoS data
frame, the MAC header domain further includes at least a QoS control field, as shown
in FIG. 13d.
[0207] When the data domain of the generated PPDU is sent by using an orthogonal frequency
division multiple access OFDMA technology, the MAC header domain of the uplink MPDU
or the downlink MPDU carried in the data domain further includes an OFDMA control
field, as shown in FIG. 13e.
[0208] Specifically, when the STA sends uplink data, data information in an attached PLCP
header domain does not need to include identifier information of the AP or the duration
information that is removed from the MAC header domain of the uplink MPDU, and includes
only some data used for channel estimation and coherent detection.
[0209] Preferably, the MAC header domain of the uplink MPDU or the downlink MPDU further
includes at least a frame control field, where the frame control field includes: an
indicator bit of a protocol version, an indicator bit of a type of a frame, or an
indicator bit of a subtype of a frame, and values of the foregoing three indicator
bits are newly added values.
[0210] Specifically, in the method of this embodiment of the present invention, the indicator
bit of a protocol version in a frame control field of the MAC header domain may be
set to a value different from a default value. The existing 802.11 protocol specifies
that the default value of the indicator bit of the protocol version in the frame control
field of the MPDU is "00"; in this case, a structure of the MPDU is shown in FIG.
4. When data carried in the MPDU is reduced, the indicator bit of the protocol version
in the frame control field of the MAC header domain may be set to a value different
from the default value, for example, "01", "10", or "11"; in this case, a structure
of the MPDU is shown in FIG. 13a, FIG. 13b, FIG. 13c, and FIG. 13d.
[0211] Preferably, in the method of this embodiment of the present invention, the indicator
bit for indicating a type of a frame in a frame control field of the MAC header domain
may further be set to a newly added value, or the indicator bit for indicating a subtype
of a frame in a frame control field of the MAC header domain may be set to a newly
added value. That is, some values of indicator bits are newly added for indicating
the control frame, the management frame, or the data frame, and some values of indicator
bits are newly added for indicating a subtype of each frame type.
[0212] For example, FIG. 13b is a data domain structure in a frame control domain for indicating
a type of a frame and a subtype of a frame, that is, a type of a sub-frame.
[0213] When an indicator bit of a frame type is "00", it indicates that the MPDU is a management
frame, and common values for indicating a subtype frame of a management frame are
"0000-1110"; in this case, in the method of this embodiment of the present invention,
an indicator bit of a type of a sub-frame may be set to "1111".
[0214] When an indicator bit of a frame type is "01", it indicates that the MPDU is a control
frame, and common values for indicating a subtype frame of a control frame are "0111-1111";
in this case, in the method of this embodiment of the present invention, an indicator
bit of a type of a sub-frame may be set to a value in a range of "0000-0110".
[0215] When the MPDU is a data frame, because all subtypes under an indicator bit "10" of
a frame type are used; in the method of this embodiment of the present invention,
the data frame may be indicated by setting an indicator bit of a frame type as "11",
and setting a subtype to a meaningful value.
[0216] It can be learned that when the STA sends uplink data, some information in the MPDU
is removed, thereby reducing redundant data and improving transmission efficiency.
[0217] It can be learned from the foregoing content that, in this embodiment of the present
invention, a control domain of a PLCP header domain in a PPDU constructed by an AP
carries identifier information of the AP, duration information, and an identifier
of at least one STA, so that a STA may obtain the identifier information of the AP,
the duration information, and the identifier of at least one STA by parsing only the
control domain of the PLCP header domain. Therefore, the STA may determine whether
the control domain of the PPDU includes an identifier of the STA and a wildcard STA
identifier according to an identifier of the AP and the identifier of at least one
STA; and further, if the STA determines that the control domain of the PPDU does not
include the identifier of the STA or the wildcard STA identifier, the STA configures
an NAV according to the duration information. In this process, only the control domain
of the PPDU is parsed, thereby improving data transmission efficiency. The wildcard
STA identifier includes identifiers of a group of STAs or all STAs.
[0218] Based on the same conception, an embodiment of the present invention provides an
AP, including a wireless local area network communications apparatus 1501 and a radio
frequency module 1502.
[0219] The wireless local area network communications apparatus 1501 may be the wireless
local area network communications apparatus in the embodiment provided in FIG. 7 or
FIG. 9, and details are not described herein.
[0220] The radio frequency module 1502 is configured to: receive a PPDU sent by a transceiver
unit or a transceiver in the wireless local area network communications apparatus
1501, modulate the PPDU into a radio frequency signal, and then send the radio frequency
signal; and receive a radio frequency signal sent by a STA, demodulate the radio frequency
signal, and then send the demodulated radio frequency signal to the transceiver unit
or the transceiver in the wireless local area network communications apparatus 1501.
[0221] Based on the same conception, an embodiment of the present invention provides a STA,
including: a wireless local area network communications apparatus 1601 and a radio
frequency module 1602.
[0222] The wireless local area network communications apparatus 1601 may be the wireless
local area network communications apparatus in the embodiment provided in FIG. 8 or
FIG. 10, and details are not described herein.
[0223] The radio frequency module 1602 is configured to: receive a radio frequency signal
sent by an AP, demodulate the radio frequency signal into a PPDU, and then send the
PPDU to a transceiver unit; and receive a PPDU sent by a transceiver unit or transceiver
in the wireless local area network communications apparatus 1601, modulate the PPDU
into a radio frequency signal, and then send the radio frequency signal.
[0224] A person skilled in the art should understand that the embodiments of the present
invention may be provided as a method or a computer program product. Therefore, the
present invention may use a form of hardware only embodiments, software only embodiments,
or embodiments with a combination of software and hardware. Moreover, the present
invention may use a form of a computer program product that is implemented on one
or more computer-usable storage media (including but not limited to a disk memory,
a CD-ROM, an optical memory, and the like) that include computer-usable program code.
[0225] The present invention is described with reference to the flowcharts and/or block
diagrams of the method, the apparatus, and the computer program product according
to the embodiments of the present invention. It should be understood that computer
program instructions may be used to implement each process and/or each block in the
flowcharts and/or the block diagrams and a combination of a process and/or a block
in the flowcharts and/or the block diagrams. These computer program instructions may
be provided for a general-purpose computer, a dedicated computer, an embedded processor,
or a processor of any other programmable data processing apparatus to generate a machine,
so that the instructions executed by a computer or a processor of any other programmable
data processing apparatus generate an apparatus for implementing a specific function
in one or more processes in the flowcharts and/or in one or more blocks in the block
diagrams.
[0226] These computer program instructions may also be stored in a computer readable memory
that can instruct the computer or any other programmable data processing apparatus
to work in a specific manner, so that the instructions stored in the computer readable
memory generate an artifact that includes an instruction apparatus. The instruction
apparatus implements a specific function in one or more processes in the flowcharts
and/or in one or more blocks in the block diagrams.
[0227] These computer program instructions may also be loaded onto a computer or another
programmable data processing apparatus, so that a series of operations and steps are
performed on the computer or the another programmable apparatus, thereby generating
computer-implemented processing. Therefore, the instructions executed on the computer
or the another programmable apparatus provide steps for implementing a specific function
in one or more processes in the flowcharts and/or in one or more blocks in the block
diagrams.
[0228] Although some exemplary embodiments of the present invention have been described,
persons skilled in the art can make changes and modifications to these embodiments
once they learn the basic inventive concept.
[0229] Obviously, a person skilled in the art can make various modifications and variations
to the present invention without departing from and scope of the present disclosure.
[0230] For example, during a process of generating (or processing) an uplink MPDU in the
foregoing implementation manners, with reference to an actual situation, it is possible
that only some information in a MAC header domain is compressed, for example, one
or a combination of a transmitter address, a receiver address, or duration information.
[0231] Specifically, when a PLCP header domain of an uplink PPDU sent by a station includes
a receiver address (such as an ID of an AP) and duration, processing may be performed
in the manner 1 or 2 of generating the uplink MPDU mentioned above. Certainly, alternatively,
the PLCP header domain of the uplink PPDU may not include the receiver address and/or
the duration; in this case, manner 3 of generating of the uplink MPDU may be used:
generating an uplink PPDU, where a PLCP header domain of the uplink PPDU does not
include one or any combination of a transmitter address, a receiver address, or duration,
and a data domain of the uplink PPDU carries an uplink MPDU whose MAC header domain
does not include at least information about the transmitter address; and
sending the uplink PPDU.
[0232] Specific examples:
Example 1a: If the PLCP header domain does not include the receiver address or the
duration, the data domain of the uplink PPDU may carry an uplink MPDU that does not
include the transmitter address.
Example 2a: If the PLCP header domain includes the receiver address but does not include
the duration, the data domain of the uplink PPDU may carry an uplink MPDU that does
not include information about the transmitter address or information about the receiver
address.
Example 3a: If the PLCP header domain includes the duration but does not include the
receiver address, the data domain of the uplink PPDU may carry an MPDU that does not
include the transmitter address or the duration information.
Example 4a: If the PLCP header domain includes the transmitter address but does not
include the receiver address or the duration, the data domain of the uplink PPDU may
carry an uplink MPDU that does not include the transmitter address.
Example 5a: If the PLCP header domain includes the transmitter address and the receiver
address but does not include the duration, the data domain of the uplink PPDU may
carry an uplink MPDU that does not include information about the transmitter address
or information about the receiver address.
Example 6a: If the PLCP header domain includes the transmitter address and the duration
but does not include the receiver address, the data domain of the uplink PPDU may
carry an uplink MPDU that does not include the transmitter address or the duration
information.
[0233] Specifically, in Example 1, when an MPDU is formed at a MAC layer, the MPDU is the
same as that in the prior art, that is, a MAC header domain of the MPDU includes the
transmitter address; when a PPDU is formed at a PHY layer, the transmitter address
in the MAC header domain of the MPDU is removed, and then the MPDU whose MAC header
domain does not include the transmitter address is put in the data domain of the PPDU.
[0234] Further, the tailored uplink MPDU sent by the STA may be further differentiated in
a scrambling manner, and scramble code used may be initialized by using an identifier
of the STA and/or an identifier of an AP. The AP receives the MPDU sent by the STA
in a specified time-frequency location in the resource indication information, and
performs descrambling on this section of data before parsing the MPDU. Scramble code
used is the same as that on a STA side.
[0235] For example, if the STA is associated with the AP, and the resource indication information
indicates that the STA sends uplink data on a specified resource, the STA removes
the transmitter address (MAC address of the STA) in the MAC header domain of the uplink
MPDU from the MAC header domain of the uplink MPDU, and sends, in the data domain
of the PPDU according to the resource indication information, to the AP, an uplink
MPDU whose transmitter address is removed. When the STA sends the uplink MPDU, the
STA sends the uplink MPDU on a specified resource according to resource indication
information carried in the downlink PPDU; accordingly, the AP receives, in the data
domain, the uplink MPDU according to the resource indication information.
[0236] The foregoing solution may also be applied to a data structure of the MAC header
domain of the uplink MPDU mentioned above. That is, manner 4 of generating the uplink
MPDU is as follows:
generating an uplink PPDU, where a PLCP header domain of the uplink PPDU does not
include one or any combination of a transmitter address, a receiver address, or duration,
and a data domain of the uplink PPDU carries an MPDU, where a MAC header domain of
the uplink MPDU does not include at least information about the transmitter address.
[0237] Specific examples:
Example 1b: If the PLCP header domain does not include the receiver address or the
duration, the data domain of the uplink PPDU may carry an uplink MPDU, where a MAC
header domain of the uplink MPDU does not include the transmitter address.
Example 2b: If the PLCP header domain includes the receiver address but does not include
the duration, the data domain of the uplink PPDU may carry an uplink MPDU, where a
MAC header domain of the uplink MPDU does not include information about the transmitter
address or information about the receiver address.
Example 3b: If the PLCP header domain includes the duration but does not include the
receiver address, the data domain of the uplink PPDU may carry an uplink MPDU, where
a MAC header domain of the uplink MPDU does not include the transmitter address or
the duration information.
Example 4b: If the PLCP header domain includes the transmitter address but does not
include the receiver address or the duration, the data domain of the uplink PPDU may
carry an uplink MPDU, where a MAC header domain of the uplink MPDU does not include
the transmitter address.
Example 5b: If the PLCP header domain includes the transmitter address and the receiver
address but does not include the duration, the data domain of the uplink PPDU may
carry an uplink MPDU, where a MAC header domain of the uplink MPDU does not include
information about the transmitter address or information about the receiver address.
Example 6b: If the PLCP header domain includes the transmitter address and the duration
but does not include the receiver address, the data domain of the uplink PPDU may
carry an uplink MPDU, where a MAC header domain of the uplink MPDU does not include
the transmitter address or the duration information.
[0238] Specifically, in Example 1b, when an uplink MPDU is formed at a MAC layer, that is,
a MAC header domain of the MPDU does not include at least the transmitter address;
in this case, an uplink MPDU whose MAC header domain does not include the transmitter
address is sent.
[0239] The foregoing solution may be applied to the apparatus and method mentioned in the
foregoing implementation manners; for example, the generation process is implemented
by using a processing unit or a processor, and a sending and receiving processes are
implemented by using a transceiver. A person skilled in the art may also understand
that the uplink MPDU and the uplink PPDU are correspondingly received and processed
on a receive side by an access point. The foregoing expanded implementation manners
and details of the implementation manners mentioned above may be logically combined,
and other expandable content is not described in this specification.